The present invention relates to rescue and rescue vehicles and, more particularly, to a recovery spade for maintaining the vehicle in a stationary position during rescue and recovery operations.
During the course of normal activities, drivers often encounter hazards that often result in vehicular misfortunes. Such misfortunes often involve one or more vehicles being directed off a public and/or private road into a trench or furrow (i.e., a ditch). Once in the trench, the vehicle becomes trapped and is unable to escape on its own. Normally, a rescue vehicle must be provided to retrieve the trapped vehicle. Rescue vehicles are known by various other names, including “wrecker” rescue vehicle, towing vehicle, tow truck, etc.
Rescue vehicles are commonly fitted with a crane member (or boom) that includes a winch and associated cable. The cable is secured to the trapped vehicle and the winch is activated to pull the trapped vehicle out of the trench. Accordingly, the winch and associated cable define a longitudinal rescue line. Rescue vehicles require a substantial amount of tractive power in order to accomplish their task. Supporting stifflegs, or recovery spades, are commonly provided at the rear of the rescue vehicle to engage the ground and increase the tractive power of the rescue vehicle. In order to maximize tractive power, the rescue vehicle should be oriented such that the longitudinal rescue line is parallel to the damaged vehicle. There are times, however, when such alignment is not practical because, for example, the rear wheels of the rescue vehicle would be positioned on compromising surfaces. There are also times when the rescue vehicle should preferably be aligned with (or positioned on) the road.
Recovery spades must be oriented transversely (i.e., perpendicular) to the longitudinal rescue line in order to maximize traction of the rescue vehicle. In situations where it is not practical, or feasible, to align the rescue vehicle with the longitudinal rescue line, conventional recovery spades cannot be oriented transversely to the longitudinal rescue line. Consequently, the maximum tractive power realizable by the rescue vehicle cannot be achieved. Rescue vehicles are often aligned with the longitudinal rescue line regardless of the environmental conditions in order to circumvent this shortcoming. Such attempts, however, place the rescue vehicle in a situation where it can slide and suffer the same fate as the trapped vehicle.
Various arrangements have been proposed for improving the tractive power of rescue vehicles and the like. For example, U.S. Pat. No. 2,928,557 issued to Cline discloses a wrecker, or hoisting apparatus, that includes means for stabilizing and preventing side slip while a service cable is used to pull a disabled automobile back onto a highway.
U.S. Pat. No. 3,127,037 issued to Newman discloses an apparatus for towing road vehicles that includes a pair of sprag-ended rods capable of engaging the ground to restrain the apparatus against movement during towing activities.
U.S. Pat. No. 4,018,458 issued to Shumaker discloses a vehicle stabilizer that consists of a pair of telescoping members, one of which includes a ground engaging foot. The stabilizer includes latch means between the telescoping member and the foot for holding the foot in a number of rotated positions relative to the telescoping member.
U.S. Pat. No. 4,245,855 issued to Larson discloses a vehicle stabilizer that includes a hydraulic cylinder pivotably mounted on each side of the vehicle. The stabilizer includes an extension rod that causes a tension member to rotate the cylinder about its pivot.
U.S. Pat. No. 4,640,660 issued to Watson discloses a recovery and towing vehicle designed to transport a freighter aircraft. The towing vehicle includes a pair of spades mounted in slideways. The spades are capable of being moved to engage the ground.
U.S. Pat. No. 4,700,852 issued to Mjoberg discloses a recovery vehicle device that includes a pair of lowerable supporting stifflegs that are capable of engaging the ground.
U.S. Pat. No. 5,431,443 issued to Skoff discloses a supporting device for a rescue vehicle that includes two legs, each of which has a footing plate located near a lateral vehicle edge of the vehicle. The legs are capable of being swiveled from a transportation position to a supporting position.
Accordingly, there is a need for a recovery spade capable of maximizing tractive power of a rescue vehicle regardless of its orientation relative to a trapped vehicle. There also exists a need for a recovery spade that can be adjusted such that it is substantially transverse with a longitudinal rescue line, regardless of the orientation of the rescue vehicle.